The invention relates to a process according to a method for introducing and adding a non-dry particulate to a material and a device for introducing and adding a non-dry particulate to a material.
Numerous processes and devices are known from the prior art in which the liquid additives are either sprayed from above onto the plastic material or added in the fluid bed process.
It is known from U.S. Pat. No. 4,522,957 to add liquid additives to plastic granules in a mixer.
In WO 00/38895, to reduce the dust nuisance or dust formation, a process of this type is further improved, in a first step, by spraying the liquid additives onto the plastic granules in a spray chamber in the countercurrent process, followed by a static mixing process.
In EP 7624, a liquid additive is added to the plastic granules, namely in an inert gas current.
In WO 84/02530, the plastic granules are first whirled in a continuous mixer and, in this turbulent state, wetted with a highly heated liquid additive in the gas stream.
A process is known from WO 9425509 in which polymer granules are wetted in a mixing device with a liquid additive via an injection nozzle, whereby, to improve the wetting, the surface of the plastic granules is structured irregularly or is roughened.
A process and a mixing device are described in WO 2006/010291 in which a liquid additive is added to plastic granules via an injection device in a mixer and the mixture subsequently reaches an extruder.
Furthermore, a process is known from EP 9817 in which the plastic granules are first wetted with a “coupling agent” or carrier which is to ensure better distribution of the liquid additive on the surface of the plastic granules. In particular, paraffins or paraffin-like substances are noted as coupling agents.
Furthermore, a process is known from U.S. Pat. No. 4,703,093 in which a liquid additive is added to already preheated plastic granules.
DE 263 16 22 describes a process for the simultaneous and continuous feeding of powdery solids and liquids in treatment machines. This occurs via a ring nozzle, wherein the liquid is formed into a tubular casing in the centre of which the solids are introduced.
However, processes of this type are primarily suitable only for highly fluid, finely sprayable additives and function only inadequately for highly viscous, sluggish additives or for additives of solid or semi-solid consistency. In most cases, the plastic material is only wetted incompletely and unevenly.
If highly viscous additives are heated to higher temperatures in order to enable them to be added nevertheless in a highly fluid form, then deposits or precipitates of the additives are often formed at cooler points or colder surfaces of the device.
This leads to difficulties and inaccuracies during dosing and to contamination of the devices.